Flame-Spread Tests in a Large Tunnel Furnace

The purpose of this paper is to describe the 25-ft flame-spread tunnel furnace and to create a better understanding of its operation, capabilities, and limitations. In this discussion, the term “flame spread” is understood to mean “flaming combustion along a surface.” As such, it is a measure of the flame-retardant properties of a material and has little or nothing to do with fire resistance or fire endurance.